Half ring gear mechanism for ultrasound inspection

The present disclosure is directed to devices and systems for inspecting pipes and tubes and more particularly, to a half ring gear mechanism for ultrasound inspection capable of performing circumferential ultrasonic pipe inspection as well as being integrated with robotic crawlers and drones.

Corrosion is one of the main threats on the longevity of pipes causing them degrade and thin. Several industries, including the oil and gas, water treatment and distribution, suffer numerous losses due to pipe degradation as it can cause the fluids contained in the pipe to leak leading to loss of production and operations halt. It can also propose a danger on individuals working near these pipes especially if these pipes are containing hazardous chemicals. To combat corrosion, regular and frequent inspections are essential to monitor the integrity of the condition of the pipes. These inspections can be done by ultrasonic thickness.

One technique for testing is a non-destructive techniques (NDT) technique. In this technique, an ultrasonic sound is applied on the pipe and its response is used to determine the pipe thickness. The drawbacks of regular inspection are the large cost and high labor demand. These drawbacks are also intensified if the pipes are located in difficult to reach locations including high positions which commonly call for the use of scaffolding.

There is therefore a need for an improved ultrasonic inspection device that overcomes the above noted deficiencies.

As mentioned above, the present disclosure is directed to an ultrasound inspection device for pipes and more specifically, is directed to a half ring gear mechanism for ultrasound inspection capable of performing circumferential ultrasonic pipe inspection as well as being integrated with robotic crawlers and drones.

In one embodiment, an ultrasonic inspection device for a pipe or tube is provided and includes an arcate shaped housing having an arcuate shaped guide slot. The arcuate shaped housing has a first end and an opposite second end spaced from the first end. A first driving gear assembly is disposed at the first end of the arcuate shaped housing. The first driving gear assembly includes a first driving gear powered by a first motor. A second driving gear assembly is disposed at the second end of the arcuate shaped housing. The second driving gear assembly includes a second driving gear powered by a second motor. An arcuate shaped driven gear travels within the arcuate shaped guide slot and is engaged at all times with at least one of the first driving gear and the second gear to permit the arcuate shaped driven gear to be driven in a 360 degree path around the pipe. An ultrasonic testing (UT) probe assembly is fixedly attached to the arcuate shaped driven gear and configured for direct contact with the pipe for performing ultrasonic inspection of the pipe or tube.

In another aspect, an ultrasonic inspection device for a pipe or tube includes an arcuate shaped housing having an arcuate shaped guide track. The arcuate shaped housing has a first lateral extension at a first end thereof and a second lateral extension at an opposite second end that is spaced from the first end. A first driving gear assembly is coupled to the first lateral extension of the arcuate shaped housing. The first driving gear assembly includes a first driving gear powered by a first motor. A second driving gear assembly is coupled to the second lateral extension of the arcuate shaped housing. The second driving gear assembly includes a second driving gear powered by a second motor. An arcuate shaped driven gear travels within the arcuate shaped guide track and is engaged at all times with at least one of the first driving gear and the second gear to permit the arcuate shaped driven gear to be driven in a 360 degree path around the pipe. In addition, an arcuate length of the arcuate shaped driven gear is greater than 180 degrees. The device further includes an ultrasonic testing (UT) probe assembly fixedly attached to the arcuate shaped driven gear and configured for direct contact with the pipe for performing ultrasonic inspection of the pipe or tube. In a first position, the arcuate shaped driven gear is disposed substantially within the arcuate shaped guide track and the ultrasonic testing (UT) probe assembly lies between the first and second ends and in a second position, the arcuate shaped driven gear is disposed substantially outside the arcuate shaped guide track and the ultrasonic testing (UT) probe assembly lies outside of the arcuate shaped housing.

The present disclosure is directed to an ultrasound inspection device for pipes and more specifically, is directed to a half ring gear mechanism for ultrasound inspection capable of performing circumferential ultrasonic pipe inspection as well as being integrated with robotic crawlers and drones.

As described in more detail below, the ultrasound inspection device of the present disclosure is generally directed to a half ring housing enclosed within it a driven gear that is configured such that more than half of the driven gear can be removed and positioned external to the half ring housing. The device further includes a driving mechanism for controllably driving the inner driven gear. In one embodiment, the drive mechanism includes two motors and an ultrasonic testing (UT) probe. In this configuration, the two motors drive two gears that are meshing with the inner driven gear to enable continuous rotation.

Now turning toin which an ultrasonic inspection deviceaccording to one embodiment is illustrated. As described herein, the ultrasonic inspection deviceis configured to be placed around a pipefor performing inspection and measurements thereof. The ultrasonic inspective devicecan be described as being a cuff.

The ultrasonic inspection deviceincludes an arcuate shaped housingthat is sized and configured for placement about the pipe.. As illustrated and described herein, the arcuate shaped housingis not placed in direct contact with the exterior surface of pipe. In the illustrated embodiment, the arcuate shaped housingcan have a semi-circular shaped and thus, can be alternatively described as being a half-ring housing. The arcuate length of the arcuate shaped housingis, in one embodiment, at least 180 degrees.

The arcuate shaped housinghas a first endand an opposite second endthat is generally opposite the first endand therefore, the first endis positioned on one side of the pipe, while the second endis positioned on the opposite side of the pipe. The arcuate shaped housingis defined by a first faceand an opposite second facewith a slot or trackbeing defined therebetween. Given the shape of the arcuate shaped housing, the trackis also arcuate shaped. The trackis open at its opposite ends. The trackopens upwardly to allow free receipt of an object, described below, into the track.

As shown, the first and second ends,can be in the form of a first lateral extension and a second lateral extension, respectively, to which other parts are mounted as discussed below.

The first faceof the housingincludes an arcuate guide slotthat is open at the two ends,of the housing. The guide slotcan be formed centrally within the first face.

At the first end(along the first lateral extension) of the arcuate shaped housing, there is a first motor housingand similarly, at the second end(along the second lateral extension) of the arcuate shaped housing, there is a second motor housing. With the first motor housingthere is a first motorand within the second motor housingthere is a second motor. Any number of conventional motors can be used, such as, electric motors that can be powered by a battery. Thus, in the case of a battery powered motor, the battery can also be contained within the motor housing.

The first motoris operatively coupled to a first drive shaftthat is driven (rotated) by operation of the first motor. The first drive shaftextends outwardly from the first motor housingin a direction toward the first face. As illustrated, the first drive shaftcan be oriented perpendicular to the face of the first motor housing. Similarly, the second motoris operatively coupled to a second drive shaftthat is driven (rotated) by operation of the second motor. The second drive shaftextends outwardly from the second motor housingin a direction toward the first face. As illustrated, the first drive shaftcan be oriented perpendicular to the face of the second motor housing.

As mentioned, the ultrasonic inspection deviceincludes a drive mechanism. The drive mechanism includes a first (driving) gearand a second (driving) gear. The first gearis operatively coupled to the first motorand more particularly, is fixedly attached to the first drive shaft. The second gearis operatively coupled to the second motorand more particularly, is fixedly attached to the second drive shaft. Each of the first gearand the second gearcan be a conventional circular toothed gear. The first and second motors,are configured to operate independently from one another; however, the two motors,are preferably in communication with a master controller that controls operation of the two motors. The master controller can send control signals to the two motors,to control operation thereof and in normal operation, the two motors,operate together and rotate in the same direction. For example, the two motors,can both rotate in a clockwise direction resulting in a first driving action as described below, or alternatively, the two motors,can both rotate in a counterclockwise direction resulting in second driving action. The speeds (RPM) of the two motors,are controlled and preferably, the speeds of the two motors,are the same.

A bearingcan be provided and coupled to the first drive shaftalong the exterior of the first driving gear. A bearingcan be provided and coupled to the second drive shaftalong the exterior of the second driving gear.

In addition, the first and second gears,are positioned so that they are aligned with the center of the track. In other words, the first and second gears,lies in a common plane that passes through the center of the track.

Another component of the drive mechanism is the driven gear. The driven gearis configured to be operatively coupled to the first and second gear,such that movement of the first and second gears,is translated into movement of the driven gear. In other words, rotation of the first and second gears,causes the driving of the driven gear. The driven gearis disposed within the arcuate shaped trackand has a complementary shape so that it can be driven within the trackin an arcuate direction. Accordingly, the driven gearhas an arcuate shape and in particular, the driven gearcan comprise an arcuate shaped gear that has an arcuate length greater than 180 degrees and more particularly, it can have an arcuate length of about 198 degrees (in this case 45% of the circumference of the driven gearhas been eliminated). The arcuate length of the trackis thus less than the arcuate length of the driven gearin which case when inserted into the track, the opposing ends,of the driven gearextend beyond the ends of the track. As described below, this construction of the driven gearallows the driven gearto be driven 360 degrees around the pipe. It will be understood that the arcuate length of the driven gearcan be less than or greater than 198 degrees so long as during 360 degree movement thereof, the teeth of the driven gearmesh at least with one of the driving gears.

The driven gearhas outwardly facing teeththat extend along the complete arcuate length of the driven gear. The teethare configured (sized and spaced) so that they mesh with the teeth of the first and second gears,(at opposite ends of the housing) to allow the driven gearto be driven in an arcuate manner when the first and second gears,rotate under action of the first and second motors,. As will be described herein and as shown in the figures, during operation one or both of the first and second gears,meshes with the driven gearas the driven gearmoves circumferentially about the pipe. As viewed from the first face (e.g., view of), when the first and second gears,are rotated in clockwise directions, the driven gearis driven in the opposite direction in that the driven gearrotates in a counterclockwise direction. Conversely, as viewed from the first face, when the first and second gears,are rotated in counterclockwise directions, the driven gearis driven in the opposite direction in that the driven gearrotates in a clockwise direction. In any event, as described herein, rotation of the driven gearin either the clockwise or counterclockwise directions allows the driven gearto travel 360 degrees about the pipe.

As shown in the figures, the half-ring shape of the driven gearpermits it to be driven circumferentially around the complete circumference of the pipegiven the constructions of the parts and operation of the motors. As shown, the housingremains in a first position about the pipeand is intended to remain stationary and has coverage over a first section (e.g., first half) of the pipe. It is the driven gearthat moves relative to both the housingand the pipeand provides coverage of the second section (e.g., second half) of the pipe. It is therefore possible to completely drive the driven gearcompletely around (360 degrees) the pipeto perform the inspection.

The drive mechanism also functions as a carrier for the ultrasonic testing equipment and more particularly, the driven gearcarries an ultrasonic testing (UT) probe assembly. The UT probe assemblyis at a fixed location along the driven gearand thus, as the driven gearis driven and moves along its arcuate pathway, the UT probe assemblymoves likewise. In the illustrated embodiment, the UT probe assemblyis fixed at a center location (arcuate midpoint) of the driven gear. However, it will be appreciated that the UT probe assemblycan be placed at other locations along the driven gear.

In the illustrated embodiment, the UT probe assemblycomprises a gear/UT couplerthat is attached to the driven gearusing conventional techniques, such as the use of fasteners (screws). As shown, the gear/UT coupleris attached to a first face (first side) of the driven gear. The gear/UT couplercan be generally U-shaped and includes first and second legsconnected with a crossbar. The gear/UT coupleralso includes a pair of hollow extrusions (extensions)that protrude outwardly from the cross barand the crossbarincludes two openings that form entrances into the hollow interior of the pair of hollow extrusions. The pair of hollow extrusionscan have cylindrical shapes as shown; however, other shapes can be equally used. Each of the hollow extrusionscan have a pair of slotsformed along sides thereof. The slotscan be linear in nature. As shown, the pair of hollow extrusionsare located radially beyond the teeth.

Since the driven gearis disposed within the trackand the gear/UT coupleris located outside the trackalong the first faceof the housing, the fasteners connecting the gear/UT couplerto the driven gearpass through the arcuate guide slotin the housing. As the driven gearis driven in the trackand the carried gear/UT couplermoves therewith, the fasteners move within the arcuate guide slot. The gear/UT couplercan seat against or be in close proximity to the first faceof the housing. The gear/UT coupleris position, as shown, such that the two legsface inward toward a center of the circle defined, in part, by the arcuate shaped housing, while the pair of hollow extrusionsface outward therefrom.

The UT probe assemblyalso includes a motor housingthat is biased relative to the gear/UT coupler. The motor housingcan have a cage like structure in that it has a hollow frameand includes a pair of protrusionsthat are configured to be received within the pair of hollow extrusions. Accordingly, the pair of protrusionshas complementary shapes and sizes for reception within the hollow spaces of the pair of hollow extrusions. In the illustrated embodiment, each protrusioncan have a cylindrical shape like the cylindrical shape of the extrusion. The pair of protrusionsare spaced apart and are parallel to one another and similarly, the pair of hollow extrusionsare spaced apart and are parallel to one another.

The biasing of the motor housingis due to the presence of a pair of springsthat are disposed between the pair of protrusionsand the inside of the hollow extrusions. In the extended state (virgin, uncompressed state), the springs push the motor housingaway from the gear/UT coupler. As the motor housingis pushed toward the gear/UT coupler, as by an applied force, the springscompress and store energy. The springscan be coil springs that seat between the protrusionsand the extrusions.

The movement of the motor housingrelative to the gear/UT couplercan be restricted and controlled by use of fasteners that act to couple the slotsof the hollow extrusionsto the motor housingto limit the movement of the motor housingin the vertical (axis) direction. For example, screws and nuts can be used to limit such movement and the protrusionscan have holes near their distal ends that can receive the fasteners that pass through the slots. The protrusionsslide in the extrusions.

The cage of the motor housingis hollow and is configured to receive a motor. The motorcan be in the form of a servo motor that is received within the cage and coupled thereto. For example, fasteners can be used to attach the motorto the cage. The first and second legsof the gear/UT couplercan be disposed along the sides of the cage of the motor housing. The motoris preferably battery powered and includes a drive shaft that is driven by the motor. The drive shaft can have a short length as shown. A motor housing lockcan be provided to ensure that motorremains securely held within the motor housing. The motor housing lockcan generally be in the form of a bracket like structure as shown.

The UT aspect and functionality of the equipment is achieved by a UT probethat is operatively coupled to the motorand more particularly, the UT probeis coupled to the drive shaftsuch that incremental movement of the drive shaftcauses incremental movement (adjustment) of the UT probe. The UT probecomprises an ultrasonic wheel probe. The wheel probe is an ultrasonic transducer assembly that allows rolling contact of a transducer over a surface.

The UT probeis coupled to the drive shaftwith a UT probe adapter. The UT probe adapteris a U-shaped structure defined by a pair of legs with a crossbar. The UT probeis disposed between the pair of legs and coupled thereto with an axle that permits the UT probeto freely rotate. The crossbar of the UT probe adaptercomprises the structure that is fixedly coupled to the motor drive shaft and therefore, when the drive shaft is rotated, the UT probe adapterrotates and likewise the UT probeitself rotates. It will be appreciated that the motoris thus utilized to change the direction of the inspection since the inspection could be along the circumference of the pipeas well as along its longitude. In, the UT (wheel) probeis oriented for traversing the circumference of the pipe. To traverse in the longitudinal direction, the UT (wheel) probewould be rotated 90 degrees.

As will be understood by one skilled in the art, the springsapply a force to the motor housingto cause the UT (wheel) probeto be pressed into contact with the pipeto ensure good contact between the UT (wheel) probeand the surface of the pipe. The springsalso permit the deviceto be used with different sizes of pipessince for larger sized pipes, the springscan compress to permit the UT (wheel) probeto be in contact with the surface of the larger pipe. In any event, the springsapply a force to the UT (wheel) probethat ensures that the UT (wheel) proberemains in contact with the pipe surface.

Combination of the Ultrasonic Inspection DeviceWith a Crawling Vehicle

illustrate the combination of the ultrasonic inspection devicewith the crawling vehicleto move the ultrasonic inspection devicealong the pipeor tub. This combination enables the scan of the entire pipeor tube since it enables the lateral and circumferential movement of the ultrasonic inspection device. The illustrated crawling vehiclefeatures magnetic wheelsto be attached on ferromagnetic surfaces as described in more detail below.

The coupling between the crawling vehicleand the ultrasonic inspection devicecan be achieved using any number of traditional techniques, including detachable coupling mechanisms that fixedly attach the two to one another. The crawling vehiclecan be coupled to the ultrasonic inspection devicenear the center of the half ring shaped housing.

The crawling vehicleincludes a large main wheelwith switchable magnetism to enable easy attachment and detachment of the vehicleto the target surface (pipe), two front magnetic wheelswith a weak magnetism to balance and prevent the crawling vehicleand ultrasonic inspection devicecombination from tipping which is critical to preserve the cuff orientation. The crawling vehiclealso features two motors. A first motoris considered to be a driving motor to drive the crawling vehicleforward and backward and a second motoris to turn and switch off the magnetism of the main wheel. Finally, the crawling vehicleincludes a chassisthat houses all the parts together.

The working principles of the crawling vehicleare as follows: (1) the magnetism of the large switchable magnet is switched on by the action of the second motor(switching motor); (2) the combined crawling vehicleand the deviceis moved to the pipe until all three of the magnetic wheels are engaged with the surface; and (3) the inspection process begins and can follow any of the scan paths described herein.

Now referring to, the design of the crawling vehiclecan be integrated with a drone. More specifically, the dronecan be securely coupled to the crawling vehiclewhich is itself securely coupled to the deviceto permit delivery of the vehicleand deviceto the target pipe. The two front magnetic wheelscan be utilized to land the droneon the ferromagnetic pipeas well as for driving the drone, and the device, along the pipe.

Operation of the Ultrasonic Inspection Device

The ultrasonic inspection deviceis based on two main working principles, namely, the engagement process and the inspection process. In the engagement process, the (half-ring) driven gearis coupled about the pipeto be inspected given that the outer diameter of the pipeis less than the inner diameter of the driven gear. The attachment of the deviceto the pipecan be done with an axillary system to the driven gearthrough magnetism if the pipeis ferromagnetic or through applied pressure if it is non-ferromagnetic. There are other method of attachment including one described below with respect to an alternative embodiment of the device.

Once the engagement process is completed, the springsin the UT probe assemblypress against the pipeand this action serves two purposes. The first is to ensure that the pipeor tube is centered within the inner diameter of the (half ring) housingfor proper circumferential UT inspection. The second is to enable the testing of the pipesor tubes with different diameters given that these diameters are less than the diameter of the (half ring) housing. In this process, the first and second motors,initially rotate the first and second gears,to rotate the driven gearoutside of the half ring shaped housing. The presence of a single UT probe assemblymeans that the single probe (UT probe assembly) has to fully rotate 360 degrees in order to scan the entire diameter of the pipe. Since the same driven gearis utilized for this rotation with 45% cut of its circumference (i.e., the driven gearhas an arcuate length of 198 degrees) that means that a single driving gear (first gearor second gear) cannot drive the driven gear360 degrees as the teeth of one single driving gear lose their meshing when the driving gear teeth reach the cut section of the driven gear. This complication is eliminated by the current design in which there are two driving gears,and two motors,at the two ends of the half ring shaped housing. In the disclosed configuration, at least one of the driving gears,will be meshing with the driven gearat every moment during its rotation.

The scanning rotation of the deviceis as follows. As previously stated, the usage of one probe (UT probe assembly) means that the driven gearhas to rotate 360 degrees in order for the single probe (UT probe assembly) to entirely scan the diameter of the pipe. The first and second motors,operate and rotate in the same direction to drive the driven gearin a 360 degree circumferential path which enables continuous scan. This is especially of value to expedite the helical path scanning. The scanning paths along the entirety of the pipeshould be very similar. Thus, after the engagement process to the pipe, the driven gearis rotated by 360 degrees in either a clockwise or counterclockwise direction to enable the probe in the UT probe assemblyto scan the entire pipe diameter.

The direction of the UT inspection for the entire pipeif it is along the circumferential or the longitude, or at an angle for the helical inspection process (will be discussed later) of the pipeshould be specified by rotating the UT probeusing the servo motorin the UT probe assembly. Following this step, the UT inspection process can start by turning on the first and second motors,which in turn will rotate the first and second (driving) gears,that mesh with the teeth of the driven gear. In the case of circumferential testing, the driven gearwill move along the pipe diameter and the measurement of the pipe thickness will be taken along it. If the inspection is meant to be taken along the pipe longitude, the (servo) motorwill adjust the orientation of the UT probefirst so that it faces the longitude of the pipe. Following this step, the first and second motors,should be utilized to rotate the UT probeto the desired clock position along the pipeor tube by the rotation of the driven gearunder action of the rotating first and second gears,. Finally, the entire device(cuff mechanism) is moved along the pipeusing suitable means including those discussed herein to get a line UT inspection along the pipe.

With intensive testing, the entire area of the pipeor tube can be inspected which is known as C-scan. In the case of the circumferential UT testing, the UT probeis rotated 360 degrees as discussed above. This process is repeated until the entire area of the pipehas been inspected. In the case of the longitudinal inspection, the entire deviceis moved from the start of the area of the pipeintended for inspection until its end. This will result in one line of measurement along the pipe. Following this movement, the first and second motors,are turned on to rotate the UT probeslightly and the deviceis moved back laterally to the start of the area resulting in another single line reading. Following this, the UT probeis again rotated slightly and the devicemoves along the pipeagain. This process is repeated until the entire pipeis inspected. Finally, the scan can be done helically by angling the UT probeslightly and continuously rotating the UT probe and moving the deviceslowly to the side. The resolution of the scan can be changed based on the distance between each test as well as the accuracy of the motors. The paths for area scanning are illustrated in the figure below.

illustrate exemplary paths of the UT probefor area scanning.shows the path for circumferential UT testing where the single UT probe() is rotated circumferentially along the pipe 360 degrees and then the device, including the UT probe, is moved sideways a short distance and another 360 degrees rotation of the UT probeis completed. This process is repeated until the entire area of the pipeis scanned.shows the longitudinal inspection path for UT probewhere the UT probescans laterally across the pipethen rotated slightly along the pipe diameter then scans the pipe laterally again by moving back to the starting point then rotate slightly along the pipe diameter and continue the process until the inspection is done.shows the helical path where the UT probeis continuously rotated at an angle with a slow and continuous sideways movement of the devicealong the pipe.

Finally, before removing the devicefrom the pipe, the driven gearshould be rotated to a position in which it is at least substantially enclosed within the half ring housingto allow the deviceto be easily removed from the pipe.

It will also be appreciated that wire guiding rings or brushed slip rings could be installed on the driven gearfor the continuous rotation of the mechanism around the pipewhile avoiding the risk of wire entanglement of the wires or wrapping them around the pipe.

The movement of the devicearound and along the pipe may introduce wheel slippage and inertial measurement drift. Accordingly, accurate localization of the UT probewill be compromised. It is essential to keep track of the accurate localization of the robot that moves the deviceand the UT probe assemblywhile performing B-Scan and C-Scan. One solution to resolve the drift and slippage problem is to anchor a stationary referencing element on the pipewhen the robot is deployed on the pipe. The reference station could attach to the pipe using switchable magnets or any other attaching mechanisms. Once the reference station is fixated on the pipe, its fixed position can be used by the robot as a localization reference. For example, the station can be equipped with a laser-beam that emits rays along the longitudinal axis of the pipe. When the robot moves helically around the circumference of the pipe, it can reset its circumference localization once it crosses the laser beam emitted by the reference station. Alternatively, the laser beam can be installed on the robotic crawler emitting laser beam towards the longitudinal direction of the docking station. When the robot moves circumferentially, it can reset its angular position when the laser beam hits the reference station. Moreover, time of flight of the laser beam can be used to measure the longitudinal crossed distance of the robot. In conclusion by using the laser beam, the robot localization drift and inaccuracy can be reset and improved which in turn will improve the accurate localization of the inspection measurement.

The ultrasonic inspection deviceprovides a number of features and advantages over conventional inspection devices. For example, the ultrasonic inspection devicedoes not need to complete engulf the pipe circumference to operate making it easier to engage with the pipe. The ultrasonic inspection devicealso can be automated and designed to be lightweight in order for the integration with drones (e.g., drone) with capabilities of performing intensive scanning. Conventional methods involve heavy manual user involvements and contain heavy components which makes their integration with drone technologies especially very difficult. This is even more critical for the inspection of small pipes since they are typically placed in congested areas and generally drone size is typically correlated to its payload carrying capabilities which makes the conventional approach unusable. In addition, conventional technologies are designed to engulf the pipe circumference to perfume their operation.

Various embodiments of systems, devices, and methods have been described herein. These embodiments are given only by way of example and are not intended to limit the scope of the claimed inventions. It should be appreciated, moreover, that the various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, configurations and locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the claimed inventions.